Probably not yet, says Tom Wenseleers, an evolutionary biologist at the Catholic University of Leuven in Belgium. Are new variants behind rising case numbers? In the background, a slew of immunity-dodging variants are emerging globally, and researchers think these will fuel an autumn–winter wave. The number of people hospitalized after testing positive for SARS-CoV-2 is rising quickly - although from low levels - in Britain and other European countries. The United Kingdom’s weekly population survey of SARS-CoV-2 infections, a gold standard in COVID-19 data, has documented an increase in COVID-19 prevalence in England and Wales in its past two reports. Some US states are already beginning to see an uptick in cases, notes epidemiologist Jennifer Nuzzo at Brown University in Providence, Rhode Island. “It could lead to some upswings as we go into the fall and winter months,” Lessler adds. And there are now subtle signs that Omicron is evolving and spawning a new generation of immunity-dodging variants. The roll-out of ‘bivalent’ boosters that target both the original SARS-CoV-2 strain and Omicron “has been a little bit slow”, says Lessler. But other factors on the horizon could spell trouble. More than a month on, hospitalizations are declining in line with projections, says Justin Lessler, an infectious-disease epidemiologist at the University of North Carolina at Chapel Hill who leads the modelling effort. New Omicron-specific vaccines offer similar protection to existing boosters Even with a new variant, a big surge in cases wasn’t certain. After surges caused by the BA.5 Omicron variant - resulting in high immunity in the population - the United States could be in for a relatively quiet COVID-19 season, the models suggested, as long as vaccine-booster campaigns began quickly and new variants didn’t emerge. In mid-August, an effort called the COVID-19 Scenario Modeling Hub laid out several possible scenarios for the United States over the coming months. Will there be a COVID-19 wave this autumn and winter? Nature explores the factors that might drive a COVID-19 wave - and what countries can do to blunt the effects with the new generation of vaccines that target Omicron. New immune-evading strains of the Omicron variant of SARS-CoV-2, behaviour changes and waning immunity mean that many countries could soon see large numbers of COVID-19 infections - and potentially of hospitalizations - say scientists.
Credit: Raj K Raj/Hindustan Times/GettyĮvidence is building that the Northern Hemisphere is on course for a surge of COVID-19 cases this autumn and winter. Social dynamics are back to pre-pandemic norms in many parts of the world.
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